A witness described a terrifying scene during an early-morning attack that left 50 people dead at Pulse Nightclub, a popular gay club in Orlando. Fifty-three people sustained injuries.

Club-goer Christopher Hansen didn’t actually see the shooter in the crowded venue, but when bodies started dropping, he hit the ground and started crawling, he told reporters after he escaped.

“When I got across the street there were people—there was blood, blood everywhere,” Hansen said. He recalled hearing loud banging sounds while inside, which he assumed was just a part of the music.

“I wasn’t sure if it was the music. I thought it was a Ying Yang Twins song,” Hansen said. “It went with the beat almost until you heard like, too many shots. That’s when you just know. It was chaos.”

Hansen tried to help a victim of the shooting by shoving a bandana he had worn into a hole left by a bullet.

“This is my first nightclub, being out,” said Hansen, who told reporters he just moved to Orlando from Ohio.

The investigation into the shooting is ongoing, but authorities have identified the shooter as Omar Mateen of Port St. Lucie, Florida.

Scenes From the Tragic Aftermath of the Orlando Pulse Nightclub Shooting

Police officers direct family members away from a shooting at Pulse nightclub in Orlando, Fla., on June 12, 2016.

Phelan M. Ebenhack—AP

Police and forensics investigators work at the crime scene of the Pulse nightclub shooting in Orlando, Fla., on June 12, 2016.

Carlo Allegri—Reuters

Friends and family members embrace outside the Orlando Police Headquarters during the investigation of a shooting at the Pulse nightclub in Orlando, Fla., on June 13, 2016.

Steve Nesius—Reuters

Police investigate the Pulse nightclub following a mass shooting in Orlando, Fla., on June 12, 2016.

Christopher Morris—VII for TIME

Tatiana Osorio cries while giving blood at the OneBlood blood center near the mass shooting at a nightclub in Orlando, Fla., on June 13, 2016. Osorio lost three friends in the shooting.

David Goldman—AP

A memorial honors the victims of the Pulse nightclub shooting at the Dr. Phillips Center for Performing Arts in Orlando, Fla., on June 13, 2016.

Christopher Morris—VII for TIME

A woman reacts as authorities investigate Pulse following a mass shooting in Orlando, Fla., on June 12, 2016.

Christopher Morris—VII for TIME

A reporter pauses at the Hampton Inn where relatives of victims gather for information in Orlando, Fla., on
June, 12, 2016.

Christopher Morris—VII for TIME

A remembrance for Eric Rivera, killed in the mass shooting at the Pulse nightclub, sits amongst a makeshift memorial for the victims in Orlando, Fla., on June 13, 2016.

David Goldman—AP

Mourners attend a makeshift vigil for victims of the Pulse nightclub shooting in Orlando, Fla., on June 13, 2016.

Christopher Morris—VII for TIME

Hundreds of people gather at a memorial outside of the Dr. Phillips Center for the Performing Arts in Orlando, Fla., on June 13, 2016.

John Taggart—EPA

A memorial honors victims of the Pulse nightclub shooting at the Dr. Phillips Center for Performing Arts in Orlando, Fla., on June 13, 2016.

Christopher Morris—VII for TIME

A mourner attends a makeshift vigil and a moment of silence for victims of the Pulse nightclub shooting in Orlando, Fla., on June 12, 2016.

Christopher Morris—VII for TIME

Reporters wait to interview relatives of victims of the Pulse nightclub shooting in Orlando, Fla., on June 13, 2016.

Christopher Morris—VII for TIME

Seddique Mateen, father of Pulse nightclub gunman Omar Mateen, outside his home in Port Saint Lucie, Fla., on June 14, 2016.

Christopher Morris—VII for TIME

President Barack Obama and Vice President Joe Biden depart a makeshift memorial after placing flowers in memory of shooting victims of the massacre at a gay nightclub in Orlando, Fla., on June 16, 2016.

Carlos Barria—Reuters

Mourners attend a makeshift vigil and a moment of silence for victims of the mass shooting in Orlando, Fla., on June 12, 2016.